Quick Answer
To drain a pool using the pool pump, turn the pump off, connect a backwash hose to the waste port, set the multiport valve to WASTE (or DRAIN), close the skimmer if pulling from the main drain, and restart the pump. Watch it closely and shut it off before it loses prime. Pumps can lower water a lot but rarely empty a pool; finish with a submersible pump.
Key Takeaways
- The WASTE setting sends water out of the backwash port without passing through the filter.
- A pump fed only by the skimmer stops pulling water once the level drops below the skimmer opening.
- Never run the pump dry; it can overheat and damage the seal within minutes.
- Fully draining an in-ground pool can cause it to float or crack; most need only a partial drain.
- Check local rules before discharging pool water and let chlorine drop close to zero first.
Lowering pool water after heavy rain, before winterizing, or to dilute high cyanuric acid or calcium is a common chore. If your system has a multiport valve, the pump you already own can do much of the work. Here is how to do it safely and when to switch to another method.
Can You Drain a Pool With the Pool Pump?
Yes, if your filter has a multiport valve with a WASTE or DRAIN setting, or a slide valve with a backwash port. Sand and many DE filters have one. Most cartridge filters do not, but you can sometimes disconnect the return hose on an above-ground pool and redirect it to a drain hose.
The limit is the water source. The pump pulls from the skimmer and, on in-ground pools, usually a main drain. Once the water drops below the skimmer opening, a skimmer-only system starts sucking air. A main drain lets you go lower, but you still have to stop before the pump loses prime.
| Method | Best for | How low it goes | Notes |
|---|---|---|---|
| Pool pump on WASTE | Partial drains with a multiport valve | Skimmer or main drain level | Fast; must be watched |
| Submersible utility pump | Full drains, cartridge systems | Nearly empty | Safe to leave with float switch |
| Garden hose siphon | Small above-ground pools | Down to the hose outlet height | Slow; needs downhill exit |
| Drain plug | Inflatable or small frame pools | Empty | Attach a hose to direct water |
Is It Safe to Drain an In-Ground Pool?
Partially draining is usually fine. Fully emptying an in-ground pool is risky because groundwater pressure under an empty shell can push a concrete or fiberglass pool upward, and an exposed vinyl liner can shrink, wrinkle or tear. Many pool builders and manufacturers warn against fully draining without professional guidance, especially when the water table is high.
Safety: Do not fully drain an in-ground pool without checking with the builder or a pool professional. Never drain right after heavy rain, when the ground is saturated, and keep the hydrostatic relief valve in the main drain clear.
What Do You Need?
- Backwash hose (often 1.5-inch, flat-lay vinyl) and a hose clamp
- Pool test kit or test strips for chlorine and pH
- Access to an approved discharge spot (sewer cleanout, lawn area or storm drain only if local rules allow)
- Submersible utility pump and garden hose to finish a full drain
- A timer or phone alarm so you check the pump regularly
How Do You Drain a Pool Using the Pool Pump?
Step 1: Check Local Discharge Rules
Many cities and counties regulate where pool water can go and require low chlorine and a neutral pH before discharge. Call your water utility or check its website. Stop adding chlorine several days ahead so levels can drop naturally, then test before you start.
Step 2: Turn Off the Pump
Shut off the pump at the switch or timer, and turn off the breaker if your timer could restart it. Always turn the pump off before moving a multiport valve handle; changing positions under pressure can damage the valve’s internal gasket.
Step 3: Connect the Backwash Hose
Attach the backwash hose to the waste or backwash port on the multiport valve and tighten the clamp. Roll the hose out to the discharge spot, keeping it flat with no kinks, and point it away from foundations, septic fields and neighbors’ yards.
Step 4: Set the Valve to WASTE
Press down on the multiport handle and rotate it to WASTE or DRAIN. This bypasses the filter and sends water straight to the backwash port. Do not use BACKWASH for draining; it pushes water backward through the filter media.
Step 5: Choose the Suction Source
If your in-ground pool has a main drain and skimmer valves, close the skimmer line and open the main drain so the pump can pull from the bottom. For skimmer-only pools, leave the skimmer open; you will only lower the water to the skimmer opening.
Step 6: Start the Pump and Monitor
Turn the pump back on and confirm a strong stream from the hose. Check every 15-30 minutes. Watch the pump basket lid: bubbles or a half-empty basket mean it is starting to draw air.
Step 7: Stop Before It Loses Prime
Turn the pump off as soon as the water reaches your target level or the skimmer begins to gulp air. Running a pump dry overheats the seal and can melt plastic parts quickly. For winterizing, many owners stop a few inches below the skimmer or returns.
Step 8: Reset the System
With the pump off, return the multiport valve to FILTER, reopen any skimmer valves, remove the hose, and refill or rebalance as planned. If you will keep running the pump, make sure the water is well above the skimmer opening first.
Step 9: Finish With a Submersible Pump if Needed
To go lower than your pump allows on an above-ground pool, drop a submersible utility pump at the deepest point with a garden hose or discharge hose attached. Many have float switches that shut off automatically. Keep extension cords on a GFCI-protected outlet.
How Long Does It Take to Drain a Pool With the Pump?
Drain time depends on pump flow and how much water you remove. Divide gallons by gallons per minute: for example, a pump moving 50 gallons per minute would need about 400 minutes, or roughly 6.5-7 hours, to move 20,000 gallons in ideal conditions. Real flow on WASTE is often lower due to hose length and lift, so lowering a foot of water is far quicker than a full drain.
Tip: Find your pool volume before you start. A rectangular pool holds roughly length x width x average depth x 7.5 gallons, measured in feet.
Troubleshooting Common Problems
- No water from the hose: The pump lost prime or the hose is kinked. Turn it off, refill the pump basket, and check the valve setting.
- Water leaks from the multiport: The spider gasket may be worn, or the handle was turned while running.
- Pump runs but flow is weak: Clean the skimmer and pump baskets and straighten the hose.
- Hose pops off: Use a proper clamp and avoid sharp bends near the valve.
- Water pooling near the house: Move the discharge farther away and downhill. Underground drain problems can make this worse; see how to unclog an underground gutter drain pipe.
When Should You Call a Pool Professional?
Call a pro if you need to fully drain an in-ground pool for resurfacing or repairs, if the water table is high, if your vinyl liner is old, or if water is dropping on its own without draining, which points to a leak. Our guide to telling if you have an underground water leak covers warning signs. While the water is low, it is a good time to service lights too; see how to fix a pool light.
Safety: Pool equipment combines water and electricity. Turn off power before servicing the pump, keep cords off wet ground, and have a licensed electrician check any equipment that trips breakers.
Frequently Asked Questions
Can I drain my pool with a cartridge filter pump?
Most cartridge filters have no WASTE setting. On above-ground pools you can disconnect the return hose and attach a drain hose, or use the filter drain plug for small volumes. For larger drains, a submersible utility pump is usually simpler and safer.
What is the difference between WASTE and BACKWASH?
WASTE sends pool water straight out of the backwash port without passing through the filter, which is what you want for draining. BACKWASH pushes water backward through the filter media to clean it, which is not meant for lowering water levels.
How low can I drain my pool with the pump?
With a skimmer-only system, only to just below the skimmer opening, because the pump then draws air. If an in-ground pool has a main drain, you can go lower, but stop well before the pump loses prime and do not fully empty an in-ground pool without professional advice.
Where can I drain my pool water?
It depends on local rules. Many areas allow discharge to a sewer cleanout or onto your own lawn once chlorine is near zero and pH is neutral, and some prohibit storm drain discharge. Check with your city or water utility before draining.
Will draining a pool damage the pump?
Not if you watch it. The danger is running the pump dry after the water drops below the skimmer or drain, which overheats the shaft seal and can melt plastic housings. Check the pump basket often and shut it off as soon as air appears.
